Battery cell

Abstract

The embodiment of the invention provides a battery cell, and relates to the technical field of batteries, the battery cell comprises a shell, and an elastic separator and at least two pole cores located in the shell, the elastic separator is located between the two adjacent pole cores to separate the two adjacent pole cores, the elastic separator is configured to be compressed and deformed under the extrusion of the pole cores when the pole cores are expanded, and the elastic separator is located between the two adjacent pole cores. Therefore, when the pole core expands, a certain expansion space is provided for the pole core through the deformation of the elastic separator, and the probability of sealing failure of the shell due to the expansion of the pole core in the use process of the battery cell is reduced.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell. Background Art

[0002] The battery cell is the core part of the battery. It is the component that carries out electrochemical reactions in the battery and is responsible for storing and releasing electrical energy.

[0003] The battery cell generally includes a pole core, a shell and a cover plate. The cover plate is used to close the two ends of the outer box to form a closed accommodating cavity between the outer box and the cover plate. The pole core is placed in the accommodating cavity, so that the pole core is protected by the shell and the cover plate.

[0004] However, during use, the electrode core may expand due to aging, physical damage, overcharging, over-discharging, etc. After the electrode core expands, the connection between the shell and the cover will loosen, resulting in a gap between the cover and the shell, causing the seal to fail, and even causing the cover to separate from the shell, affecting the safety of the battery cell. Summary of the invention

[0005] The embodiment of the present application provides a battery cell to absorb the expansion of the battery cell and reduce the probability of loose connection between the cover plate and the shell.

[0006] An embodiment of the present application provides a battery cell, comprising a shell, and an elastic separator and at least two pole cores located in the shell, wherein the elastic separator is located between two adjacent pole cores to separate the two adjacent pole cores, and the elastic separator is configured to be compressed and deformed by being squeezed by the pole core when the pole core expands.

[0007] In a possible implementation, the elastic separator includes a main body portion made of a heat-conductive material and a resilient portion made of an elastic material, the main body portion has a receiving cavity, and the resilient portion is located in the receiving cavity.

[0008] In a possible implementation manner, the rebound portion includes a plurality of groups of support members, each group of the support members includes two oblique ribs with opposite inclination directions, and two ends of the oblique ribs are respectively connected to two opposite side walls of the accommodating cavity.

[0009] In a possible implementation, a mounting hole is provided at least at one end of the shell, an end of the main body is inserted into the mounting hole, and an end surface of the main body is flush with an outer surface of the shell or extends beyond the outer surface of the shell.

[0010] In a possible embodiment, the shell includes an outer shell, a first cover plate and a second cover plate, the outer shell has an installation cavity, the first cover plate and the second cover plate are respectively connected to two ends of the outer shell to close the two ends of the installation cavity, and the pole core and the elastic separator are both located in the installation cavity.

[0011] In a possible implementation manner, two ends of at least one side wall of the housing are bent in a direction away from the installation cavity to form an outwardly protruding installation portion, and the first cover plate and the second cover plate are correspondingly connected to the two installation portions.

[0012] In a possible implementation, the mounting portion includes a buffer section and a connecting section, the buffer section is tilted, one end of the buffer section facing away from the pole core is connected to the connecting section, and one end of the connecting section facing away from the buffer section is connected to the first cover plate or the second cover plate.

[0013] In a possible implementation, at least one first welding groove is provided on one end of the connecting section away from the buffer section, and second welding grooves are provided on the first cover plate and the second cover plate, and the first welding groove and the second welding groove cooperate to accommodate a weld scar.

[0014] In a possible implementation manner, a heat conductive member is disposed in the installation cavity, and the heat conductive member is used to fill a gap between the pole core and the second cover plate.

[0015] In a possible implementation manner, the heat conducting member is an elastic member.

[0016] The battery cell provided in the embodiment of the present application is provided with a shell, an elastic separator and at least two pole cores. The pole core and the elastic separator are both located in the shell. The elastic separator is located between two adjacent pole cores, which can separate the adjacent pole cores and also limit the pole cores. In addition, when the pole core expands, the elastic separator can be compressed and deformed due to strong squeezing, thereby reducing its own thickness, providing a certain space for the pole core to expand, and reducing the probability of the shell failing to seal due to deformation, thereby having a better protective effect on the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0018] Figure 1 A schematic diagram of the structure of a battery cell provided in an embodiment of the present application;

[0019] Figure 2 Schematic diagram of the structure of the elastic separator in the battery cell provided in the embodiment of the present application Figure 1 ;

[0020] Figure 3 Schematic diagram of the structure of the elastic separator in the battery cell provided in the embodiment of the present application Figure 2 ;

[0021] Figure 4 A schematic diagram of the connection structure between the elastic separator and the shell in the battery cell provided in an embodiment of the present application;

[0022] Figure 5 A schematic diagram of the connection structure between the first cover plate and the outer shell in the battery cell provided in an embodiment of the present application.

[0023] Reference numerals:

[0024] 100-housing;

[0025] 110-housing;

[0026] 111-installation part;

[0027] 1111-buffer segment;

[0028] 1112-connection segment;

[0029] 112-first welding groove;

[0030] 120-first cover plate;

[0031] 121- second welding groove;

[0032] 130- second cover plate;

[0033] 131-mounting hole;

[0034] 140-installation cavity;

[0035] 150-heat conducting member;

[0036] 200-core;

[0037] 300-elastic separator;

[0038] 310-main body;

[0039] 311- boss;

[0040] 320-rebound part;

[0041] 321-oblique reinforcement;

[0042] 330-accommodation chamber.

[0043] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0044] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0045] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0046] Electrochemical reactions take place inside the battery cell to charge and discharge, which may cause the battery cell to swell during use for a variety of reasons, such as the following:

[0047] 1. Overcharge: Overcharging may cause the electrolyte to decompose and produce gas, which will cause the core to expand and increase in volume;

[0048] 2. Over-discharge: Over-discharge may cause chemical instability inside the battery cell, generate gas, and cause the core to expand;

[0049] 3. High temperature: When the battery cell is used in a high temperature environment, the electrolyte decomposition will be accelerated, causing the core to expand;

[0050] 4. Aging: As the battery cell is used, the internal material of the core may change, causing the core to expand;

[0051] 5. Thermal runaway: When the pole core experiences thermal runaway, it will cause the pole core to expand rapidly.

[0052] The outer shell and cover of the battery cell are generally connected by welding. After the core expands, the outer shell will deform, making the weld at the connection between the outer shell and the cover easy to fail due to the deformation of the shell. Especially when the battery cell has thermal runaway, the core will excessively expand. At this time, the weld between the outer shell and the cover may fail quickly, making it easier for thermal runaway to spread, resulting in increased losses.

[0053] In order to avoid the above-mentioned problems, an embodiment of the present application provides a battery cell, which is provided with a shell, an elastic separator and at least two pole cores. The pole core and the elastic separator are both located in the shell, and the elastic separator is located between two adjacent pole cores, which can separate the adjacent pole cores and also limit the pole cores. In addition, when the pole core expands, the elastic separator can be compressed and deformed due to strong squeezing, thereby reducing its own thickness, providing a certain space for the pole core to expand, and reducing the probability of the shell sealing failure due to deformation, thereby providing better protection for the battery cell.

[0054] It can be understood that the battery cells mentioned in the embodiments of the present application include but are not limited to lithium-ion battery cells, lithium polymer battery cells, nickel-metal hydride battery cells, nickel-cadmium battery cells, lead-acid battery cells and other common battery cells, and this embodiment does not limit them here.

[0055] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0056] In some embodiments, see Figure 1 As shown, the battery cell includes a shell 100 and at least two pole cores 200 . The pole cores 200 are located in the shell 100 , and the shell 100 protects the pole cores 200 .

[0057] Exemplarily, the shell 110 includes a shell 110, a first cover plate 120 and a second cover plate 130, and the shell 110 has an installation cavity 140. The first cover plate 120 and the second cover plate 130 are respectively sealed and connected to the two ends of the shell 110 to close the installation cavity 140 from both ends, that is, the two ends of the installation cavity 140 are open and closed by the first cover plate 120 and the second cover plate 130 respectively, and the pole core 200 is located in the installation cavity 140. In order to fix the pole core 200, the pole ear of the pole core 200 can also be connected to the first cover plate 120.

[0058] The first cover plate 120, the second cover plate 130 and the housing 110 can be connected by welding, which has a certain connection strength and can be sealed. Of course, the first cover plate 120, the second cover plate 130 and the housing 110 can also be connected by other common methods as long as they can be sealed, and this embodiment does not limit them here.

[0059] It is understandable that the structure of the shell 110 is only an example and not a limitation. The shell 100 may also be other structures as long as it can protect the pole core 200. This embodiment does not limit it.

[0060] In some embodiments, see Figure 1 As shown, the battery cell also includes at least one elastic separator 300, which is located in the shell 100. At least one elastic separator 300 is arranged between two adjacent pole cores 200 to separate the two adjacent pole cores 200 through the elastic separator 300. At the same time, the elastic separator 300 can also be compressed and deformed when the pole core 200 expands due to the strong squeezing of the pole core 200, thereby reducing the occupied space, thereby leaving more space in the shell 100 for the pole core 200 to expand, effectively reducing the probability of the shell 100 being directly deformed due to the expansion of the pole core 200.

[0061] Among them, the elastic separator 300 is at least partially made of a material with a certain elasticity. On the one hand, it can fit with the pole core 200 through the rebound ability of the elastic material, support and limit the pole core 200, and assist in conducting the heat of the pole core 200. On the other hand, when the pole core 200 expands, it can be compressed and deformed due to the extrusion of the pole core 200, thereby reducing the space occupied by the elastic separator 300, effectively absorbing the expansion of the pole core 200 during normal use, and reducing the probability of deformation and sealing failure of the shell 100.

[0062] In some embodiments, see Figure 2 and Figure 3 As shown, the elastic separator 300 includes a main body 310 made of a heat-conductive material and a resilient portion 320 made of an elastic material. The main body 310 has a receiving cavity 330 , and the resilient portion 320 is located in the receiving cavity 330 .

[0063] Exemplarily, the main body 310 can be a metal with good thermal conductivity, such as aluminum, copper, etc., which has both certain ductility and high thermal conductivity. When in contact with the pole core 200, it can quickly conduct heat. When the battery cell is working normally, the main body 310 can assist in controlling the temperature of the pole core 200. When the battery cell is thermally runaway, the heat of the pole core 200 can be quickly drawn out through the position in contact with the pole core 200, thereby reducing the temperature of the pole core 200 and helping to reduce the degree of reaction inside the pole core 200.

[0064] For example, see Figure 2As shown, the rebound portion 320 is a plurality of groups of support members made of elastic material, and the elastic material may be carbon steel, stainless steel, phosphor bronze, alloy steel, nickel alloy, etc. Each group of support members includes two oblique ribs 321, and the inclination directions of the two oblique ribs 321 are opposite, and the two ends of the oblique ribs 321 are respectively connected to the two opposite side walls of the accommodating cavity 330 to form a triangular support structure. Of course, these two side walls are preferably the side walls of the main body 310 used to fit with the pole core 200, so as to effectively support the main body 310 through the oblique ribs 321 and position the pole core 200.

[0065] Among them, the support members are arranged in sequence along the extension direction of the accommodating cavity 330, that is, the X direction in the figure. At this time, each group of support members can be set in the same direction or in opposite directions, that is, the triangular support structure formed by the two oblique ribs 321 of each group of support members can be facing the same direction or in opposite directions. It can be understood that arranging in opposite directions can enhance the support effect.

[0066] For example, see Figure 3 As shown, the rebound portion 320 may be a block-shaped structure made of elastic materials such as rubber, which is adapted to the shape of the accommodating cavity 330 and can be directly filled in the accommodating cavity 330 .

[0067] In some embodiments, see Figure 4 As shown, at least one end of the shell 100 is provided with a mounting hole 131 , the end of the main body 310 is inserted into the mounting hole 131 , and the end surface of the main body 310 is flush with the outer surface of the shell 100 or extends outside the outer surface of the shell 100 .

[0068] Exemplarily, mounting holes 131 may be opened on the second cover body, the number of the mounting holes 131 matches the number of the elastic partitions 300, and the end of the main body 310 extends out of the second cover plate 130 through the mounting holes 131, so that the main body 310 can contact with the equipment for adjusting the temperature of the battery cell, thereby assisting in adjusting the temperature of the pole core 200.

[0069] Of course, the main body 310 and the second cover plate 130 are sealed and connected. The specific connection method can be selected according to actual conditions, and this embodiment does not limit it.

[0070] For example, see Figure 4 As shown, a connecting column can be set at one end where the main body 310 is connected to the mounting hole 131. The size of the main body 310 is larger than the size of the connecting column, so as to form a boss 311 at the end where the main body 310 is connected to the connecting column. When the connecting column is inserted into the mounting hole 131, the boss 311 abuts against the end of the mounting hole 131, which can limit the depth of the connecting column inserted into the mounting hole 131 and also help improve the sealing effect and reduce the risk of leakage.

[0071] Among them, in order to facilitate the insertion of the connecting column into the mounting hole 131, a guiding slope can be set at one end of the mounting hole 131 facing the mounting cavity 140 to form a trumpet-shaped structure at this end. Of course, the shape of the connecting column is also adapted thereto. When the connecting column is inserted into the mounting hole 131, since the size of the end of the connecting column away from the mounting cavity 140 is smaller than the size of the end of the mounting hole 131 facing the mounting cavity 140, it is easier to insert the connecting column into the mounting cavity 140.

[0072] In addition, the hole wall of the mounting hole 131 and the connecting column can be connected by welding. In order to avoid exposure of the weld, a third welding groove can be set on the end of the connecting column and the hole wall of the mounting hole 131 away from the mounting cavity 140. The two third welding grooves cooperate with each other to form a groove body for accommodating the weld, and the weld is completely hidden in the groove body.

[0073] It is understandable that the elastic partition 300 and the housing 100 may also be connected in other common ways, which is not limited in this embodiment.

[0074] In some embodiments, see Figure 5 As shown, at least two ends of a side wall of the housing 110 are bent in a direction away from the mounting cavity 140 to form an outwardly protruding mounting portion 111 , and the first cover plate 120 and the second cover plate 130 are connected to the two mounting portions 111 accordingly.

[0075] The battery cell may expand during use, especially when the battery cell is in thermal runaway, the pole core 200 may expand more violently, such as Figure 5 As shown by line B in the figure, the pole core 200 will push the side wall of the housing 110 to bulge away from the mounting cavity 140, thereby affecting the weld between the housing 110 and the first cover plate 120 and the second cover plate 130, resulting in failure of the seal at the connection. In this embodiment, at least one side wall of the housing 110 that is opposite to the pole core 200 is concave relative to the position connected to the first cover plate 120 and the second cover plate 130. When the pole core 200 expands, as shown in FIG. Figure 5 As shown by line A in FIG. 1 , the expansion amount generated by the pole core 200 first impacts the concave side wall of the shell 110 , which can reduce the impact on the weld between the shell 110 and the first cover plate 120 and the second cover plate 130 , and reduce the probability of sealing failure.

[0076] The distance between the end of the mounting portion 111 connected to the concave portion of the main body 310 and the welding scar in the X direction is at least 1 mm, so as to improve the protection effect on the welding scar.

[0077] In addition, in practical applications, the pole core 200 has wider sides, and when the pole core 200 expands, it is mainly these two sides that expand. Therefore, the mounting portion 111 can be arranged on the side wall of the housing 110 opposite to the side of the pole core 200 that mainly expands, so as to better absorb the expansion of the pole core 200.

[0078] It is understandable that the mounting portion 111 may also be provided on other side walls of the housing 110 , and may be suspended according to actual needs, which is not limited in this embodiment.

[0079] In some embodiments, see Figure 5 As shown, the mounting portion 111 includes a buffer section 1111 and a connecting section 1112 . The buffer section 1111 is tilted, and the end of the buffer section 1111 facing away from the pole core 200 is connected to the connecting section 1112 . The end of the connecting section 1112 facing away from the buffer section 1111 is connected to the first cover plate 120 or the second cover plate 130 .

[0080] Specifically, in the X direction, the higher end of the buffer segment 1111 is used to connect to the connecting segment 1112, and the lower end is used to connect to the concave part of the main body 310, thereby playing a better buffering role during the expansion of the pole core 200, so as to further reduce the probability of damage to the weld between the outer shell 110 and the first cover plate 120 and the second cover plate 130 due to the expansion of the pole core 200.

[0081] The connecting section 1112 may extend along the X direction or be inclined, as long as it can effectively connect the buffer section 1111 and the first cover plate 120 and the second cover plate 130 , and this embodiment does not limit it.

[0082] In some embodiments, at least one first welding groove 112 is provided at one end of the connecting section 1112 away from the buffer section 1111, and a second welding groove 121 is provided on the first cover plate 120 and the second cover plate 130. The first welding groove 112 and the second welding groove 121 cooperate to accommodate the weld scar, thereby effectively reducing the protruding size of the weld scar.

[0083] In some embodiments, a heat conductive member 150 is disposed in the mounting cavity 140 , and the heat conductive member 150 is used to fill the gap between the pole core 200 and the second cover plate 130 .

[0084] Specifically, the two ends of the pole core 200 are generally not flat, and there may be components such as pole ears, which causes the end of the pole core 200 to not completely fit with the second cover plate 130. Generally, the equipment for cooling or heating the pole core 200 will conduct heat through contact with the second cover plate 130. This embodiment adds a heat conductor 150, and the heat conductor 150 fills the gap between the pole core 200 and the second cover plate 130, which can effectively improve the thermal conductivity between the pole core 200 and the outer shell 110 and ensure the heat transfer efficiency.

[0085] It is understandable that the heat conducting member 150 only needs to be able to conduct heat effectively and fill the gap between the pole core 200 and the second cover plate 130 , and this embodiment does not limit it.

[0086] Exemplarily, the heat conductor 150 is an elastic member, that is, the heat conductor 150 can be made of an elastic material with high thermal conductivity, such as thermal conductive silicone, thermal conductive rubber, thermal conductive gel, etc. After the heat conductor 150 is placed between the pole core 200 and the second cover plate 130, the weight of the pole core 200 presses on the heat conductor 150, and the heat conductor 150 will automatically deform and fit tightly with the end of the pole core 200 and the second cover plate 130 to effectively transfer heat.

[0087] Exemplarily, the heat conductor 150 can be made of a hard material with high thermal conductivity, such as copper, aluminum, etc. The shape of the end of the heat conductor 150 in contact with the pole core 200 is adapted to the end shape of the pole core 200, and the shape of the end in contact with the second cover plate 130 is adapted to the shape of the second cover plate 130, thereby effectively contacting the pole core 200 and the second cover plate 130 to improve the thermal conductivity effect.

[0088] An embodiment of the present application also provides an electrical device, which includes a device body and at least one battery cell in the above embodiment, and the battery cell is used to supply power to the device body.

[0089] It can be understood that the device body of this embodiment includes but is not limited to wearable devices, household appliances, portable audio devices, electric vehicles, electric bicycles, electric scooters, emergency equipment, etc. As long as they are powered by batteries, this embodiment does not limit them.

[0090] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the application disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the claims.

[0091] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A battery cell, characterized in that: The invention comprises a shell (100), and an elastic separator (300) and at least two pole cores (200) located in the shell (100), wherein at least one elastic separator (300) is arranged between two adjacent pole cores (200) so as to separate the two adjacent pole cores (200) through the elastic separator (300), and the elastic separator (300) is configured to be compressed and deformed by being squeezed by the pole core (200) when the pole core (200) expands.

2. The battery cell according to claim 1, characterized in that: The elastic separator (300) comprises a main body (310) made of a heat-conducting material and a resilient part (320) made of an elastic material; the main body (310) has a receiving cavity (330); and the resilient part (320) is located in the receiving cavity (330).

3. The battery cell according to claim 2, characterized in that: The rebound portion (320) comprises a plurality of groups of support members, each group of the support members comprises two oblique ribs (321) with opposite inclination directions, and two ends of the oblique ribs (321) are respectively connected to two opposite side walls of the accommodating cavity (330).

4. The battery cell according to claim 2, characterized in that: At least one end of the shell (100) is provided with a mounting hole (131), an end of the main body (310) is inserted into the mounting hole (131), and an end surface of the main body (310) is flush with the outer surface of the shell (100) or extends outside the outer surface of the shell (100).

5. The battery cell according to claim 1, characterized in that: The housing (100) comprises an outer shell (110), a first cover plate (120) and a second cover plate (130); the outer shell (110) has an installation cavity (140); the first cover plate (120) and the second cover plate (130) are respectively connected to two ends of the outer shell (110) to close the two ends of the installation cavity (140); the pole core (200) and the elastic separator (300) are both located in the installation cavity (140).

6. The battery cell according to claim 5, characterized in that: The two ends of at least one side wall of the housing (110) are bent in a direction away from the installation cavity (140) to form an outwardly protruding installation portion (111), and the first cover plate (120) and the second cover plate (130) are correspondingly connected to the two installation portions (111).

7. The battery cell according to claim 6, characterized in that: The mounting portion (111) comprises a buffer section (1111) and a connecting section (1112); the buffer section (1111) is arranged obliquely; an end of the buffer section (1111) facing away from the pole core (200) is connected to the connecting section (1112); an end of the connecting section (1112) facing away from the buffer section (1111) is connected to the first cover plate (120) or the second cover plate (130).

8. The battery cell according to claim 7, characterized in that: At least one first welding groove (112) is provided at one end of the connecting section (1112) facing away from the buffer section (1111), and second welding grooves (121) are provided on the first cover plate (120) and the second cover plate (130), and the first welding groove (112) and the second welding groove (121) cooperate to accommodate a welding scar.

9. The battery cell according to any one of claims 5 to 8, characterized in that: A heat conducting member (150) is arranged in the installation cavity (140), and the heat conducting member (150) is used to fill a gap between the pole core (200) and the second cover plate (130).

10. The battery cell according to claim 9, characterized in that: The heat conducting member (150) is an elastic member.

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